INSTRUMENTATION PART 10: CURRENT METER INSTALLATION

With the battery voltage meter part of the instrumentation project finished. It was time to move on to the important current meter part of the project. BIANKA already had a Xantrex XBM battery monitor but, to see it required that I move away from the helm and lift a cockpit hatch and bend down to see it. It was awkward and inconvenient to look at while underway.

I went looking for another meter that could measure the current being drawn from or charging the battery bank. But, the catch was I did not want to have to put in another shunt for measuring  current in the battery circuit like the XBM battery monitor already used. I wanted to keep any extra connections to a minimum. To do that I needed to use a hall effect type of current meter.  It determines a current value by measuring the magnetic flux around a piece of wire with current flowing through it. I found exactly what I needed with a company called Devicecraft. They had a hall effect current meter with a transducer that would fit the 2 AWG wires that connect to  BIANKA's 48 volt electric propulsion battery bank.



The hook up is farely simple.


The display required a supply voltage and three wires that go to the hall effect transducer.  I needed to run the transducer wires about eight feet and used some   Twisted Servo Hookup Wire,   normally used in things like model cars and planes:

Like I did for some of the wires for the battery voltage meters part of this project I enclosed the transducer wires in a  Techflex General Purpose 1/4-inch Braided Cable Sleeve.  This was to keep the wires together and also protect them from chafing.

The 100 amp Hall effect sensor will fit over the 2 AWG cable that is used in the my electric propulsion system but, would not fit over the existing lug. So I needed cut the existing battery cable. I used a ratcheting wire cutter like a Klein ratcheting cable cutter which cuts heavy duty battery cable easily:

and makes a nice flush cut:

I took the opportunity to trim some other 2 AWG  battery interconnections that were a little too long from my initial electric propulsion installation five years ago too.  The Hall Effect transducer has a polarity in terms of it's display. That is if you a drawing current from the battery the display should show a negative sign in the display. Likewise when charging the battery it is useful to see the current flow as positive (no minus sign) on the digital display.  In order to make sure I got the polarity right I used some of the trimmed battery cables and a jumper to check the polarity of the meter.

Once I had established the proper orientation for the sensor I put it on the battery cable and crimped a new lug on the end and reconnected it to the battery. I then ran the sensor wires up through the cockpit wire conduit I made and into the helm area using one of the  Fiberglass Wire Pull Rods    I carry on board:

It was then just a matter of hooking up the sensor and power wires to the current display and the instrumentation project was finished:

I mounted it the box temporarily at the helm and used it on my fall cruise up the Hudson River and back. I still need to make a permanent platform for the box at the helm location but, that is a project for another day.

HELM INSTRUMENTATION PROJECT PART NINE CLICK HERE

HELM INSTRUMENTATION PROJECT PART ONE CLICK HERE

A LIGHT PROJECT

I bought another BEBI BEKA LED light for the boat. I find it to be a rugged and versatile light for use on board. It can also serve as a backup anchor light should the one on the top of the mast fail at anytime. I've also mentioned before how much I like to use Anderson Power Pole connectors for various uses on board the boat.  So with the new light on board and a spare 12 volt cigarette power plug I came up with an adapter project that will come in useful:

First I used a Crimper made for the Anderson Power Poles to crimp connectors for the BEBI Beka LED light:

I then checked with an ohm meter the positive wire of the cigarette lighter plug. This is important step to make sure you have the correct polarity in the wiring of the connectors. If wrong you could blow a fuse at worse you could have an electrical fire on board. Best to avoid both situations by checking the wiring:

Once the connectors are crimped on the wires they are inserted into the Anderson color coded housing and are ready to go and be used in various configurations on board:

For example I use the BEKA light for nighttime illumination in the cockpit. But, I could also easily add an extension cable between the cigarette plug and the BEKA light and hoist it up the mast as an emergency anchor light if needed.

CHECKING THE MAST LIGHTS

I pull the mast on BIANKA every year. I do this because having the mast up while the boat is on land puts stresses on the boat that are not as large when it is in the water because the hull does not move as on a mooring. It also allows me to have easy access to the chain locker and the windlass motor. It also allows me to inspect the mast and checkout the wiring and lights since the mast is on ground level.  I've mentioned how much I like to use Anderson Powerpole Connectors on board for connections. It also allows me to make various  adapters that help in testing various items around the boat.

 Using a small 12 battery and adapters made using Anderson Powerpole Connectors  and matching connectors for the mast fittings makes checking the mast light wiring an easy task.

ON BIANKA'S BOOKSHELF: Books of an electric sailor

I've seen a number of posts recently  on various sailing sites of people wanting to find books on gaining knowledge about all things electrical on board their boats. I have two books on board BIANKA that I consider worth having on board. One is Boatowner's Mechanical and Electrical Manual: How to Maintain, Repair, and Improve Your Boat's Essential Systems by Nigel Calder.

My dog eared and oil stained copy has been on board since I first purchased BIANKA back in 1995. Since I converted to electric propulsion there are now whole chapters concerning diesel engines and alternators I can now ignore. But, others especially those concerning electrical wiring and extensive coverage of batteries have come in very handy. For example I purchased a heavy duty crimper to make the crimps on the 2 AWG wire interconnects for the electric propulsion battery bank. Unfortunately, my crimper had markings only for metric sized wires. I opened Calders book and found a conversion chart that allowed me to set the crimper to the proper setting. It's information like that which can save the day when you are in some far away anchorage trying to make repairs.The Boatowner's Mechanical and Electrical Manual : How to Maintain, Repair, and Improve Your Boat's Essential Systems is also available for the Kindle.

The other book which I find useful is  Boatowner's Illustrated Electrical Handbook by Charlie Wing. It contains a lot of information about the various electrical systems one would find on board and the theory of how they work. There's DC and AC theory covered as well as things like bonding and corrosion issues. Wiring color codes and a number of charts and formulas as well. The Boatowner's Illustrated Electrical Handbook is also available as a Kindle e-book download. 

Both books are worthy of the space they take up on board. Both are very useful if you just want to understand about electrical systems and devices on board your boat, need to do some repairs or even rewire your boat. After converting to electric propulsion I find them even more valuable to have on board.

BATTERY TO DO LIST OF AN ELECTRIC SAILOR

Because of the charging issue with one of my propulsion batteries it is the first time in four years that I have had to actually squeeze my six foot two inch frame down below the cockpit to work there. I've had an  item on my to do list concerning the batteries for those four years. That was to replace the electric tape covered terminals with something more robust and protective. When I first I looked around I could not find exactly what I was looking for to protect these terminals. But, eventually I found something I could modify to work. It is the  Rotating Cable Cap from Blue Sea Systems:

They can help insulate the battery terminals better than just wrapping them up with electrical tape.

 
In order to use the Blue Sea Caps I had to modify the base part using a box cutter or razor blade to notch out an opening to accommodate the battery terminals as shown below:

Below  is the end result. It does not have to be perfect but, just big enough to allow the battery tab fit.

The photo below shows the base part of the Blue Seas cap installed over the battery terminal. The upper cap attaches to the base part to help protect the terminal and rotates in the direction of how the wire is run to the terminal. But, both can be removed easily too for cleaning and servicing.

Since I'm down below connecting and disconnecting the battery cables it seems like a good time to finish up the last item concerning the battery bank.

TOOLS OF AN ELECTRIC SAILOR: Ratcheting Crimper

A lot of people I know seem to get by using a cheap wire crimper/stripper that look like this:
  I do have a pair on the boat and few around the house too. They do work and I keep them around as backups. But, the crimps you make with them tend to distort the connectors and can be of a questionable mechanical strength. For my wiring and rewiring projects on board BIANKA I use a more robust ratcheting crimper like this one:

It won't release until you have made a good strong crimp. It has three sizes color coded dies for the proper sized insulated connectors. There are no wire stripper blades on it. It is designed to do one thing and that is to make a good solid crimp. It is the right tool for the job when it comes to making crimps on connectors. That's why it's in my electrical tool kit on board.